March 2014, Volume 10, Issue 3

Published by AEGIS Communications

Practice Boosters

Recent trends in restoratives—including direct composites and CAD/CAM all-ceramics, along with in-office procedures like tooth whitening—are broadening the scope of treatments that can be performed completely within the dental practice. For dentists and their teams, these capabilities represent an opportunity to capitalize on returning consumer confidence after the overall decline in patient demand for elective treatments that occurred concurrently with the economic downturn. The slight rise in consumer spending is bringing increased patient interest in cosmetic, minimally invasive, and restorative treatments, and other procedures that can be performed in the dentist’s office in one—or at least fewer—appointments.

Trends in Esthetic Dentistry

“Americans will be demanding more esthetic dentistry. After 4 years, all elective facial services—rhinoplasty, blepharoplasty, facial plastic surgery, esthetic dentistry—are increasing, so we are seeing an up check in the amount of esthetic dentistry being performed,” observes Roger Levin, DDS, chairman and chief executive officer of Levin Group, Inc. “Now, it’s a slight up check, but I’m very optimistic it’s going to increase year by year going forward as a continuation of what began before the recession.”

Recent surveys are indicative of this upswing. A 2012 survey conducted by the American Academy of Cosmetic Dentistry (AACD) found that AACD dentists were performing, on average, 61 whitening treatments per year. Approximately 29% of dentists responding cited this as an increase, and 45% of those surveyed expected the number of whitening treatments they performed to increase for 2013.1

Fortunately, in-office materials, techniques, and procedures have evolved to make treatment processes easier, more predictable, and more convenient for dentists and patients. Gerard Kugel, DMD, MS, PhD, associate dean for research at Tufts University School of Dental Medicine and editor-in-chief of Inside Dentistry, says that direct composites and bonding systems have become easier and more efficient to use. Better composite polishability with nanocomposites is an important improvement for direct composites. In addition, matrix systems for posterior restorations also have improved, helping facilitate better outcomes.

Patients are spending money for these direct restorative procedures as well. The 2011 American Dental Association (ADA) Survey of Dental Fees reported that general practitioners charged on average from $153 to $282 per posterior direct composite resin restoration, and from $139 to $344 per anterior direct composite resin restoration, depending on the number of surfaces involved.2

Newer materials and technologies are allowing dental professionals to repair teeth and change esthetics without sacrificing as much tooth structure as in years past. More and more patients are becoming educated about minimally invasive esthetic dentistry, and practices are enhancing their level of training to respond to the demand to be less aggressive, notes Jack Ringer, DDS, accredited AACD member and 2013-2014 AACD president.

“Rather than placing a crown, dentists will provide an inlay or a veneer. This is just good dentistry, not just because the patient is asking for it, but because the reality is that nothing we have in dentistry is as good as a natural tooth,” Dr. Ringer adds.

To help dental practices champion a more minimally invasive approach to smile enhancements and necessary treatments, teeth whitening, direct composite restorations, and in-office CAD/CAM procedures can be incorporated and planned alone or in combination to satisfy patient needs. “Whitening is easy; composites are completely common place; but a much bigger investment is required to incorporate CAD/CAM,” says Dr. Levin. “I think whitening will increase slightly for the first time in 4 years, and it will continue to improve. With CAD/CAM, we are seeing more dentists with these chairside units, and the majority are successful with them.”

Whitening

The AACD considers tooth whitening to be any process that lightens teeth.3 The ADA Council on Scientific Affairs labels tooth whitening, or vital bleaching, one of the most cost-effective and conservative treatments for those wishing to enhance their smiles.4 Its benefits for patients include that it is extremely convenient, relatively inexpensive, and one of the least invasive smile enhancement methods available.

A multitude of professional whitening systems are available. Practices charge anywhere from $250 to $400 for take-home trays, and fees for in-office power bleaching generally start at around $450 per treatment and top out at as much as $800.5

According to Dr. Levin, whitening is an area of practice that can be grown even within a non-growing practice. Most offices have only whitened less than 10% of their patients, he says.

“The best whitening option is still take-home trays, which whiten the best and produce easily maintained results,” believes Robert Margeas, DDS, a lecturer and private practitioner. “In-office procedures will whiten teeth, but over time patients will still need to wear trays in order to maintain the effect.”

Best practices for teeth whitening include proper gingival isolation (ie, for in-office procedures) and thoroughly disclosing the pros and cons—as well as what’s involved in the process—to patients. Dr. Kugel also notes that patients should be advised of the possible need for following up an in-office procedure with take-home whitening, or for wearing the trays for a longer period of time.

Caveats and considerations for whitening also include patient characteristics, such as their level of sensitivity, and type of discoloration (eg, tetracycline stains). Whitening’s efficacy still depends on contact time and concentration of the active ingredients, so patients who want whiter teeth will wear trays longer, and use a higher concentration of bleach. However, lower concentrations worn overnight are still the best when it comes to bleaching, Dr. Margeas says.

Resin Composites

Direct composites can be selected for a variety of restorative indications, from lengthening teeth to repairing fractures, and from masking dark or discolored dentition to closing diastemas.6 Although there are myriad options available to clinicians, there is currently no one perfect material on the market for every clinical situation.7

With a variety of direct composites available, it can be challenging to determine what’s most appropriate for a given case. New developments in resin composites include bulk-fill composites, self-adhesive composites, syringeable universal composites, and composites with improved blending and esthetics when layered, explains John Powers, PhD, senior vice president and editor of The Dental Advisor. These new composites may result in improved clinical performance.

In recent years, resin composite sales have risen significantly, whereas sales of amalgam, formerly the go-to material for direct restorations, have seen substantial decreases. Contributing to this trend is the fact that today’s direct composites display balanced color stability8 and are highly polishable, which is critical in mimicking natural dentition.9 Their proper use is still predicated on careful judgment calls. Optical and physical characteristics—including color, shade, durability, and strength—should be carefully considered when choosing a composite material.10 Because direct composites are so often used to restore incisal edges of anterior dentition, where they are exposed to masticatory and occlusal forces, resin composites must be durable.11

However, the success and longevity of direct composite restorations also demand the use of an adequate curing light and proper placement on the restoration to achieve polymerization. Jack L. Ferracane, PhD, chair of restorative dentistry and the division director of biomaterials and biomechanics at Oregon Health & Science University, advises dentists to ensure that their curing unit delivers ample irradiance (ie, 600-1000 or so mW/cm2, depending on the size of the light guide). He also urges them to light cure for at least 20 to 30 seconds, especially if the curing light is at the low end of the output mentioned.

“You can have the best composite in the world, but if you don’t use it correctly, place sectional matrices for Class II restorations, isolate properly, follow adhesive protocol, and light-cure fully, then the material isn’t going to work,” Dr. Kugel emphasizes.

What remains unknown about all curing units is the uniformity of the light emitted from the tip, although this is being investigated and reported by some researchers, Dr. Ferracane adds. An uneven light distribution across the tip face (ie, “hot” and “cold” spots with high and low intensities, respectively) may require moving the light over the surface, rather than holding it steady, to deliver a more uniform cure. He suggests that LED lights are the way to go, and that if a dentist’s quartz tungsten halogen light ceases to work, an LED is the best option.

“It is generally believed that near optimal curing for resin composite requires about 15-20 J/cm2, so for a light with 1000 mW/cm2 output, 20 seconds is a good amount of curing time,” Dr. Ferracane says. “I am skeptical of lights with very high power and proposed shorter curing times, in large part because it is likely that most dentists don’t deliver all of the output of the light to the restorative material in the most efficient way.”

CAD/CAM

Perhaps no other innovations have transformed the way clinicians practice quite like CAD/CAM and digital technologies, which have helped revolutionize and simplify the way that restorations are created. Since its inception in dentistry nearly three decades ago, CAD/CAM use has steadily increased substantially.12,13 In an August 2010 survey conducted by Dental Products Report, 58% of respondents reported owning digital x-ray systems or digital sensors, while an additional 21% of those surveyed planned to purchase some sort of system.14

Open architecture and ever increasing ease-of-use could be the reasons. With open architecture systems, dentists don’t need to purchase all of their equipment and software from one company, Dr. Ringer explains. They could buy a milling unit from one company, but use a scanning system for digital impressions from another, because open architecture enables the different devices to communicate and work together.

Lower costs represent another reason, Dr. Ringer says. “Dentists can have a chairside milling unit in their office much less expensively than it was even 5 years ago,” he says. “In the long run, it will be less expensive, dentists won’t have laboratory costs involved, and once they’ve recaptured the cost of the CAD/CAM unit, most expenses will be for materials.”

From an efficiency and production standpoint, CAD/CAM and digital technologies present huge opportunities, Dr. Levin adds. Once dental staff members are trained, CAD/CAM restorations can be fabricated in-office very efficiently. Dentists and their teams typically pick up speed after completing about 20 or more CAD/CAM restorations. He emphasizes that every new technology and procedure has a learning curve, but once dentists and their staff work through it, CAD/CAM is a highly efficient technique.

This efficiency is also providing patients with benefits, such as same-day dentistry for indirect restorations that are now more convenient. They no longer need to schedule multiple appointments for one restoration; rather, everything can usually be accomplished in one visit. Although appointments per patient may be longer, control over the entire workflow process resides within the practice.

Enhancing the attractiveness of in-office CAD/CAM treatments is the quality of the materials and blocks for milling and seating these restorations. Dr. Kugel says today’s millable materials have made a big difference in the application of in-office CAD/CAM, citing that posterior crowns can now be fabricated chairside, since materials like lithium disilicate are sufficiently strong.

“If a lesion is too large for placing a direct composite restoration, that’s when dentists turn to indirect restorations,” Dr. Margeas explains. “Dentists can mill them chairside, or prepare the teeth, take a digital or conventional impression, and have the laboratory fabricate the restoration.”

According to Dr. Powers, ceramics based on lithium disilicate and lithium silicate have higher strength than feldspathic porcelains. These ceramic restorations that can be milled in the office or prepared in the dental laboratory have an excellent clinical track record. The Dental Advisor has reported excellent clinical performance based on long-term recall data of IPS e.max Press (5 years), Dr. Powers says.

“When dentists are running an efficient practice, then they schedule knowing that they’re doing a CAD/CAM restoration that day. A well-trained staff can perform many CAD/CAM tasks (eg, taking digital impressions, designing the restoration, staining and glazing), so it can be very profitable if it’s done correctly,” Dr. Kugel observes, adding that taking radiographs to ensure a sealed margin is significant to ensuring that CAD/CAM restorations fit properly. “If it takes half a day to make one restoration, then it’s not profitable.”

Conclusion

Maximizing the use and advantages of these in-office procedures depends on continuous education and training as much as an affinity for evolving patient needs. “As a member of the AACD, I see the need to realize a higher standard of esthetics that people want, and those aren’t very generic or pedestrian,” Dr. Ringer says. “Regardless of the technology involved, dentists and their teams will benefit from a much more elevated skill set, and dentistry is heading in that direction for anterior esthetics.”

According to the Levin Group Data Center, 75% of dental practices have declined in production in the past 5 years, creating the need to do more with the patients they already have. One way to accomplish this is increasing the number of services provided, such as whitening and same-day dentistry. Although many practices may offer these services, Dr. Levin says that they aren’t providing them at their full level of potential.

“I think what needs to be emphasized more than the materials or equipment is the care taken to do dentistry well,” asserts Dr. Ferracane, adding the need for attention to the manufacturer’s directions for the use of specific products. “I feel pretty confident that manufacturers have provided dentists with a wide range of good, quality products, but it is up to the dentist to use them appropriately, in the right situations, and with skill to provide the best result for their patients. It should seem obvious, but doesn’t always seem to be the case.”

Spotlight On:

Bulk-Fill Composites

Bulk-fill/cure direct composites, which are available in two forms, are gaining traction in the marketplace. They can be used either as a thick liner (ie, up to 4 mm) cured in bulk and then capped off with another direct composite, or as a full restorative that can be cured in up to 4 to 5 mm increments, depending on the claims of the brand.

“The difference in these materials compared to traditional composites, which cannot be bulk-filled, is that the materials are manufactured to transmit more light to greater depths because they are a bit more translucent, and/or by having an additional photochemical initiator,” Dr. Ferracane elaborates, adding that some traditional composites do cure up to several millimeters. “All of these materials are designed to produce less polymerization contraction stress than traditional composites, thus reducing the worries about bulk curing and its effect on stress at the bonded interface.”

Claims of a 4-to-5-mm depth of cure and reduced stress seem to be true from tests that Dr. Ferracane and others have performed. Most liner materials have lower mechanical properties and should not be used as definitive restoratives on occlusal surfaces. Ultimately, how all of these materials will perform still needs to be determined, he says.

However, the concept of bulk composite placement is one step closer to the ideal material, Ferracane believes. Another step would be self-adhesive composites not just as liners, but as definitive restoratives that do not require a separate bonding agent. Both of these advances would be very attractive to dentists, since they would greatly simplify and speed up the placement of posterior composites, he suggests.

Spotlight On:

Microfilled Composites

Microfilled composites are filled with tiny particles averaging 0.04 micrometers. Although they may often lack strength, they are suitable for esthetic restorations in the anterior. Microhybrid composites contain a variety of larger and smaller particle sizes to provide a combination of strength, wear resistance, and polishability. Nanohybrid composites, developed in response to issues regarding handling, wear, and esthetics, contain an average particle size of 1 micrometer and are indicated for use in a variety of clinical situations.

However, there may be limited quality research available for some direct composites, cautions Dr. Kugel. In particular, any study performed without a control or a randomized control group may not provide a realistic view of a product’s capabilities and limitations.

“We don’t see many clinical studies prior to products reaching market, partly because not all dentists demand them, nor are they required for many of these products,” Dr. Kugel says. “Research results we see are usually from bench studies.”